Yes, the cost of trademark registration can depend on the number of classes of goods and services that your trademark application covers.
In many countries, the trademark registration fees are structured in a way that requires separate fees for each class of goods or services included in the application. The fees are typically set by the intellectual property office or authority responsible for trademark registration in that particular country.
For example, if your trademark application covers a single class of goods or services, you will generally pay the base filing fee for that class. However, if your application includes multiple classes, you will need to pay additional fees for each additional class.